1. Field of the Invention
The present invention relates to a sustained release pheromone preparation which releases a sex pheromone substance into air to control an insect pest having a carboxylic acid compound as a pheromone substance by mass trapping or mating disruption.
2. Description of the Related Art
It is important for establishing a control technology with pheromone to sustainedly release a sufficient amount of pheromone from an attraction source to attract wild insect pests with respect to the mass trapping, and to maintain a sufficient amount of pheromone to cause mating disruption in an entire region to be controlled with respect to the mating disruption. Because an insect pest generally emerges over a long period of time, typically from spring to autumn, sustained release of a pheromone substance from a sustained release pheromone preparation comprising the pheromone substance makes the mass trapping or the mating disruption possible over the entire period of emergence. Thus, to establish a pheromone-based control technology, development of a sustained release pheromone preparation for the insect pests to be controlled is very important.
In order to release a constant amount of an active component over a long period time, a sustained pheromone preparation is in form of a sealed container, wherein the container includes a cap, a small tube, a laminate envelope and a capsule and is made of a material having an ability to control a release amount. The material includes rubber, polyethylene, polypropylene, an ethylene-vinyl acetate copolymer containing 90% by weight or greater of ethylene repeating units, and polyvinyl chloride (JP 11-069936A). Among them, polyolefin-based plastics, which typically include polyethylene, are available in various grades with different properties so that they come in a broad range of selection as a material. The polyolefin-based plastics are also widely used so that they are inexpensive. Further, the polyolefin-based plastics excel in moldability and can be molded in various ways such as extrusion molding, film molding, stretch molding and injection molding. The polyolefin-based plastics excel in mechanical strength, particularly in mechanical strength at low temperature so that they can be suitably used during a time of low temperature period or in a low temperature region. Moreover, aldehyde or acetate compounds, which are contained by most of the pheromone substances for the insect pests in Lepidoptera, can be comprised by a sustained release pheromone preparation with a polyethylene membrane and result in a control effect (JP 57-009705A).